This invention relates to a compressible pad for supporting a hardwood floor, particularly a hardwood sports floor, above a base.
For many indoor athletic venues, particularly venues where basketball is a major indoor sport, hardwood floors remain the playing surface of choice. Hardwood floors provide uniform performance characteristics over a relatively long period of time. Hardwood floors are aesthetically pleasing, and properly designed and installed hardwood floors help to minimize wear and tear on the bodies of the athletes performing on the surface.
Typically, to minimize wear and tear, hardwood sports floors provide some amount of vertical xe2x80x9cgive,xe2x80x9d or deflection, which results from the use of resilient pads which support the floor above a base. In many cases the pads are arranged in parallel rows along the bottom surfaces of a subfloor structure, and floorboards are secured to the top of the subfloor. A typical resilient hardwood floor system of this type has been sold for a number of years by the assignee of the present application, under the trademark PERMACUSHION.
With this type of floor, because the subfloor and the upper floorboards are supported in spaced relation above the base via the pads, there exists a certain amount of vertical clearance space between the under side of the subfloor and the base, thereby allowing air circulation. This helps to minimize potential problems which may otherwise be caused by the ontake or egress of moisture by the wooden floor components, either due to flooding or moisture resulting from humidity in the air.
The particular composition and structure of the pads helps to determine the overall vertical deflectability, or resiliency of the floor structure located above. That is, to provide the desired vertical deflection, prior hardwood floor pads have come in a number of different shapes and sizes. Often the pads include void spaces to accommodate some desired amount of deflection, with the void spaces opening either in the vertical direction or in horizontal direction.
But for many athletic venues, particularly in venues where the cost constraints may be greatest, the preferred hardwood floor may be a relatively simple structure of the type described above, with an upper layer of floorboards supported on a subfloor, most likely parallel spaced rows of attachment members laid end to end, and supported above a base by a plurality of uniformly distributed pads. For these floors the pads must provide a desired amount of vertical spacing above the base and vertical deflectability for the upper floor surface when the floor is in use. Also, because the weight of the subfloor and the floorboards supplies some amount of initial compression to the pads, i.e., when in a xe2x80x9cstatic loadedxe2x80x9d condition, the design, the shape and composition of the pads must take into account the degree of compression of the pad in the static loaded condition, and the further compressibility of the pad which is available when the pads are xe2x80x9cloadedxe2x80x9d due to additional force or weight applied to the floor above.
One commonly used pad for floors of this type includes spaced upper and lower pieces held apart by a plurality of parallel rows of vertical supports defining a plurality of parallel rows of rectangularly-shaped horizontal passages between the upper and lower pieces. The rectangularly-shaped passages within the pads provide some amount of void space to facilitate compression of the pads, to a degree determined by the material of the pad, the amount of loading to the floor, and the density and/or distribution of the pads used to support the floor. Typically, these pads are integrally molded, as by extrusion. This particular pad has proven well suitable for extended time in supporting hardwood floors in many athletic venues.
Nevertheless, as a result of testing the compressibility of these pads, particularly the restoring forces of these pads, i.e., the ability of the pad to reassume its original state, i.e., to decompress, to the static loaded condition, can be improved. For instance, with these pads, it has been experienced that in some cases the parallel longitudinal supports may buckle sideways after being subjected to excessive vertical loads, or loads over a long period of time. Moreover, because the upper layer of floorboards may expand and contract due to moisture ontake and egress, as a result of humidity changes, and because the pads usually frictionally engage the base, even in a static state the pads may be subjected to and required to withstand some horizontal sheer forces. These sheer forces may promote, or accelerate, the undesired buckling of the supports. Once buckling occurs, the pads can eventually become transformed into incompressible masses. This can significantly reduce the resiliency of the floor, or even make the resiliency negligible.
It is an object of this invention to improve the durability and to extend the life of a relatively low cost hardwood floor system of the type described above.
It is another object of the present invention to improve the restoring force, or restoring capability of the resilient pads used to support a hardwood floor in spaced relation above a base, and to do so in a relatively cost efficient manner within a given vertical profile.
It is still another object of the present invention to minimize the adverse effects on a floor system which may otherwise result from horizontal sheer forces applied to the pads by the floor components and the base.
The present invention achieves the above stated objects via a pad design which incorporates a plurality of parallel trusses, or legs, which extend between upper and lower sections of the pad, the legs being angled and offset and defining a plurality of parallel triangularly-shaped openings which extend from one side of the pad to the other, with every other triangularly-shaped opening being inverted with respect to the adjacent opening or openings.
Because each of the legs is angled to oppose the direction and the orientation of an adjacent leg or legs, this pad design better controls deformation under static loaded conditions and also under performance load conditions, when athletes are playing on the hardwood surface above. Moreover, the angled legs maximize the restoring forces of the pad, so that the pad will be better able to repeatedly resume its original static loaded condition, for an extended period of time. This translates into a longer wear life for the floor, and ultimately, lower costs.
According to the preferred embodiment of the invention, a plurality of pads are secured to the underside of attachment members, in this case sleepers, laid end to end and arranged in spaced parallel rows over a base. An upper floor surface is then secured transversely to the sleepers, preferably by fasteners such as nails. If the upper floor surface comprises a plurality of tongue and groove floorboards laid end to end, then the nails are angled to secure the floorboards to the sleepers, as is well known in the industry. With the upper layer of floorboards secured to the sleepers, the pads support the floor, i.e., the subfloor and the floorboards, in spaced relation above the base, in a static loaded condition. That is, the legs deform slightly to accommodate the weight of the floor above.
When the floor is in use, i.e., when additional weight or force is applied to the floor, the pads provide a further degree of deflectability for the floor, the delectability resulting from further vertical compression of the pads beyond the static loaded condition. When the weight or force is removed, the pads are better able to vertically decompress to restore the floor to its original static condition, due to the orientation of the angled legs and the parallel openings which are uniformly triangular in cross-sectional shape along their lengths.
Because of the improved ability of the pads to withstand vertical compression and the improved ability to decompress, over an extended period of time, the present invention reduces the need to prematurely replace a floor due to the pads becoming incompressible masses, or blobs, residing between the subfloor and the base. Also, because of the orientation and shape of the legs and the openings, the pads of this invention are better able to withstand vertical sheer forces applied to the pads by the floor components, forces which result from expansion or contraction of the floorboards.
These and other features of the invention will be more readily understood in view of the following detailed description of the drawings.